Generally, as shown in FIG. 1, a conventional lamp air exhausting apparatus comprises a compression head 1 including a head 6 connected to a vacuum system (not shown), a cap 2 engaged with the head 6, and a rubber ring 3 disposed between the head 6 and the cap 2. Further, an exhausting tube 4a is formed at the end of a lamp 4, and, if the exhausting tube 4a is fitted to the head 1, and if the cap 2 is turned, a push portion 5 secured to the lower portion of the cap 2 will press against the rubber ring 3, so that a seal is formed between the lamp 4 and the head 6 so that when head 6 is subjected to the vacuum, the air in the lamp will be exhausted.
However, the lamp 4 is provided with an electrode 7 at the center of the end of the lamp 4, and a lead 7a of the electrode 7 is secured to the lower portion of the lamp 4 in a state with the electrode 7 installed at the center of the tip of the lamp 4. Consequently, the exhausting tube 4a had to be separately provided for carrying out the air exhaust.
As a result, it is not an easy task to install the electrode when forming the lamp, as well as in locating the center. Further, the provision of the separate exhausting tube causes complication of the manufacturing process, thereby lowering the productivity.